Visualization of Flows in Beds Packed With Spheres

The figure shows an oil tunnel and associated equipment used in experiments, using the full-flow-field tracking (FFFT) technique, to characterize flows in beds packed with poly (methyl methacrylate) spheres. The indices of refraction of the oil and the spheres were matched to make the spheres invisible to the eye and cameras. The oil was seeded with magnesium oxide particles as flow tracers. The packed bed and the seeded oil in its interstices were illuminated with laser light in a plane aligned along the direction of bulk flow, thereby making visible some aspects of the flow dynamics. The image of the illuminated plane was recorded by a television camera aimed perpendicularly to the flow. The light sheet was traversed from one side of the tunnel to the other to acquire image data in different planes for use in synthesizing a three-dimensional image of the entire flow field.